1. Field of the Invention
This invention relates generally to the field of musical drums, and is more particularly directed to an externally mounted adjustable damping system for a drumhead.
2. Description of the Related Art
Modern drumheads are typically constructed of single or multiple layers of synthetic plastic materials such as polyethylene, polypropylene, polyester and the like. A drumhead sheet of plastic material is formed to a shape that will fit over the open end of a drum shell. The peripheral edges of the formed drumhead sheet are secured within a rigid drum hoop, typically constructed of metal. Tensioning devices engage the hoop and adjustably tension the drumhead over the drum shell. Generally speaking, higher tension on the drumhead produces higher pitch vibrations when the drumhead is struck.
Plastic sheet materials have proven to be exceptionally durable, attractive and adaptable to the manufacture of drumheads for musical drums. Synthetic sheet materials, however, also have some undesirable vibration characteristics that have come to the attention of both musicians and sound engineers. Synthetic drumheads have a tendency toward sustained vibration where the peripheral portions of the drumhead emit unwanted ringing and overtones that detract from the sound of the primary fundamental tones of the drum.
Undesirable sustain and overtones are particularly a problem with bass drums. The desirable vibration pattern for bass drums is usually a sharp initial sound of the fundamental tone when the drumhead is struck (the attack of the drumhead) followed by a rapid suppression of further vibration. This vibration pattern permits each bass drum strike to be distinctly heard, even if the drum is struck rapidly, as in rock, jazz, Latin and other forms of popular music. Sustain is undesirable in a bass drum because it can lead to a muddled sound in the low frequency portion of a musical arrangement. The deficiencies of synthetic drumheads have become particularly apparent with the widespread use of highly sensitive and accurate digital recording technology.
Various approaches have been taken to suppress undesirable sustain and/or unwanted overtones in a synthetic bass drumhead. For example, tape and other laminations have been applied to the outside (playing) surface of the drumhead. Although this technique has been somewhat successful, it has been less than satisfactory in a number of respects. Perhaps most notably, the laminated material is relatively thick and thus muffles desirable sounds as well as unwanted overtones. The thickness of the lamination also alters the feel of the drum and can detract from the clarity and crispness of the fundamental tones produced when the drumhead is struck (the attack characteristics of the drumhead).
Various vibration-damping systems have been developed for attachment to or placement adjacent to the interior surface of a drumhead. U.S. patent application Ser. No. 09/492,221, assigned to the assignee of the present invention, discloses a marching bass drumhead muffle ring. The muffle ring comprises a ring of plastic sheet material affixed between the inside surface of a drumhead and the bearing surface of a drum shell. The ring is biased toward the drumhead so that damping elements inserted between the plastic ring and the interior surface of the drumhead are biased against the drumhead interior surface. The drumhead muffle ring may include a complete ring of damping material or arcuate sections of damping material positioned to tune the drumhead as desired. The thickness, composition and radial width of the ring or segments of damping material may also be varied. While this arrangement permits variable adjustment of drumhead vibration, adjustment is made quite difficult because the drum must be disassembled, reassembled and tuned for each setting.
U.S. Pat. No. 5,892,168 illustrates a drumhead with floating muffling ring affixed to the interior surface of a bass drumhead. The floating muffling ring includes a ring of damping material laminated to a ring of biasing material. This ring of laminate is adhesively affixed to the periphery of the interior surface of the struck or batter drumhead of a bass drum. When a beater strikes the batter drumhead, the initial force of the strike moves the damping material away from the drumhead, permitting the initial vibration to be somewhat unsuppressed. The biasing element urges the damping material back into contact with the drumhead so that subsequent vibrations are suppressed, particularly those of the peripheral portions of the drumhead.
There are several disadvantages to this arrangement. First, the arrangement is not adjustable. Once adhered to the interior surface of the batter drumhead of an assembled bass drum, the floating muffling ring cannot be removed and the damping effect may not be adjusted. Also, the damping element is constantly urged into contact with the drumhead by the biasing layer of the laminate, which causes an undesirable deadening of the attack characteristics of the drumhead.
The understanding in the art was that placement of damping elements on the playing surface of a drum is undesirable for cosmetic reasons. Thus, many arrangements are configured for application to the inside surface of the drumhead membrane. Access to the damping system for removal or adjustment is seriously complicated by this arrangement. Also, since a beater strike initially displaces the drumhead membrane toward the interior of the drum shell, damping systems disposed adjacent to the interior surface of the drumhead cause an undesirable suppression, or deadening of the initial attack characteristics of the drum.